Dongtai Increases Investment in Austrian Subsidiary Tongan GmbH by EUR 8.8 Million

Date of Announcement: August 13, 2026 Date of Statement: August 12, 2026 Time of Statement: 18:02:21 Company Code: 4526 Company Name: Dongtai Subject: Increase in Investment in Austrian Subsidiary - Tongan GmbH Applicable Clause: Clause 20 Date of Event: August 12, 2026

Details: 1. Name and Nature of the Subject (For preferred shares, specify issuance terms such as dividend rate): Tongan GmbH; Ordinary Shares

2. Date of Event: August 12, 2026 ~ August 12, 2026

3. Board Approval Date: August 12, 2026

4. Other Approval Dates: Not applicable

5. Transaction Quantity, Unit Price, and Total Transaction Amount: Number of Units: Not applicable Unit Price: Not applicable Total Transaction Amount: EUR 8,800,000 (approximately NT$327,624,000)

6. Counterparty and Relationship with the Company (If the counterparty is an individual and not a related party of the company, name disclosure may be omitted): Counterparty: Tongan GmbH Relationship with Company: 100% owned subsidiary of the company

7. If the counterparty is a related party, state the reason for selecting them, previous transferor, relationship between previous transferor and the company and counterparty, transfer date, and transfer amount: Reason: Improvement of overall operational structure and funding needs Previous Transfer Date and Amount: Not applicable

8. If the owner of the subject matter was a related party of the company within the past five years, disclose the date, price, and relationship at the time of acquisition and disposal: Not applicable

9. Matters related to the disposal of receivables (including types of collateral attached to disposed receivables; if receivables are from related parties, disclose the name and book value of the receivables): Not applicable

10. Gain (or loss) from disposal (not applicable for acquisition of securities) (if previously deferred, explain recognition status): Not applicable

11. Delivery or payment terms (including payment schedule and amounts), contractual restrictions, and other important agreements: Delivery or Payment Terms: Phased investment according to funding needs Contractual Restrictions and Other Important Agreements: None

12. Decision-making method for this transaction, reference basis for price determination, and decision-making unit: Company Audit Committee and Board of Directors

13. Net asset value per share of the securities-issuing company acquired or disposed: Not applicable

14. Cumulative number, amount, ownership percentage, and restricted rights (e.g., pledge status) of securities held to date (including this transaction): Amount: EUR 36,935,000 (approximately NT$1,375,090,050) Ownership Percentage: 100%

15. Cumulative investment in securities listed under Article 3 of the 'Asset Acquisition and Disposal Handling Guidelines for Publicly Issued Companies' (including this transaction) as a percentage of total assets and equity attributable to owners of the parent in the company's most recent financial statements, and the amount of working capital in the most recent financial statements: Percentage of total assets: 13.22% Percentage of equity attributable to owners of the parent: 27.45% Working capital amount in most recent financial statements: NT$896,973,000

16. Broker and brokerage fees: Not applicable

17. Specific purpose or use of the acquisition or disposal: Long-term investment

18. Dissenting directors' opinions on this transaction: None

19. Whether this transaction is a related-party transaction: Yes

20. Date of auditor committee approval or audit committee consent: August 10, 2026

21. Whether the accountant issued a non-reasonable opinion: No

22. Name of accounting firm: Not applicable

23. Name of accountant: Not applicable

24. Accountant's license number: Not applicable

25. Whether it involves a change in business model: No

26. Explanation of business model change: (Blank)

27. Transaction status with the counterparty in the past year and expected in the next year: Not applicable

28. Source of funds: Bank loan

29. Previous date of material information disclosure for the same event: Not applicable

30. Other explanatory matters: The company plans to increase capital in its 100% Austrian subsidiary 'TONGAN GmbH'. Following this, 'TONGAN GmbH' will increase capital in its 100% Austrian subsidiary 'mbi-group Beteiligung GmbH', which will then increase capital in its 100% Austrian subsidiary 'ANGER MACHINING GmbH'.